Final answer:
The real estate activity involving the sale, purchase, or lease of businesses is referred to as Business Brokerage, a specialized sector dealing with various business types, including sole proprietorships, partnerships, and corporations.
Step-by-step explanation:
Real estate activity related to the sale, purchase, or lease of businesses is referred to as Business Brokerage. This type of brokerage specializes in transactions that involve the transfer of ownership of businesses. This can include a variety of business types such as sole proprietorships, partnerships—including both general and limited partnerships—and corporations. Partnerships are often utilized among professionals like doctors and lawyers, or in situations where the startup costs would be too great for an individual. In contrast, a corporation is a more formal business entity that requires government approval to be established and can offer shares to the public if it chooses to become a public company.